Rhesus monkeys (Macaca mulata) have been utilized extensively as a pre-clinical model in hematopoietic stem cell transplant research. In order to carry out such research, it is important to be able to identify and isolate the hematopoietic stem cells from rhesus bone marrow or peripheral blood. Recently, BCRP has been focused upon as a marker for the very primitive hematopoietic or other organ stem cells.
Stem cells have the capacity to become at least all differentiated cell types of their lineage in that tissue. Stem cells have two important characteristics that distinguish them from other types of cells. First, they are unspecialized cells that renew themselves for long periods through cell division. Secondly, under suitable conditions they can be induced to become cells with special functions, which may be considered differentiated.
Stem cells have been identified in a variety of tissues. They can be distinguished by a variety of means, such as by the tissue from which they were harvested, their bias in differentiation ability, the stage of development at which they exist, and their gene expression profile. In particular, stem cells may be from ectoderm (epidermal, neural, neural crest, and hair follicle); mesoderm (cardiac muscle, skeletal muscle, umbilical cord blood, mesenchymal, hematopoietic, umbilical cord matrix, and multipotent adult precursor); endoderm (pancreatic islet and hepatic oval); and germ (primordial germ) stem cells. More than one stem cell may be present in a particular tissue. For example, in the hematopoietic system alone, there are stem cells from the yolk sac, fetal cord blood, liver, and adult bone marrow.
Although stem cells may be derived from any tissue harboring stem cells, in particular embodiments they are from bone marrow, embryos, mesenchyme, neural tissue, pancreatic tissue, muscle tissue (such as cardiac muscle), liver, skin, intestine, nasal epithelium, bone, pancreas, or germ cells, for example.